1. Field of Invention
The invention relates to urinary catheters used for draining the bladder of patients who cannot void or empty their bladders for various reasons, or may not be able to control their urinating.
2. Description of Prior Art
Three types of urinary catheters are in use. One is a straight rubber catheter which is inserted through the penis or female urethra, held in place until the bladder is empty and then removed. A second type is the so-called Foley rubber catheter which is fashioned with a balloon at the inner, inserted end which may be inflated after insertion for retention of the inner end of the catheter within the bladder, urine being continuously drained through the catheter for as long as is necessary. The outer, downstream end of the catheter is generally attached to a bag which may be carried by the patient or hung on the patient's bed. The Robinson catheter represents a modification of the simple Foley catheter in providing for infusion of solutions into the bladder as well as the urinary draining function. A third type known as a Condum catheter is commonly used with patients who do not have control of urination. In this type a prophylactic is drawn over the penis and is connected by a rubber tube to a bag which the patient carries or which may be hung on the patient's bed.
All of the prior art catheters have one problem in common, viz, frequency of infection. Whenever a catheter is placed into the bladder for urinal drainage, there is a very high incidence of infection. The Foley and Robinson catheters, if left in the patient for over a week, produce infection in practically 100% of the cases. The incidence of infection of just one single straight catheterization is as high as 1%.
Urinary infections are a tremendous everyday medical problem. Introduction of infection not only produces discomfort, fever and acute illness, but may eventually cause the kidneys to become infected and cease their function, a disease condition called chronic pyelonephritis.